The ensnare is an active spell. Just like sneak attack they made it way worse. It should work the same way! As a passive on weapon attack easly done with new reactions. Same thing for hail of thorns. instead of letting me use it twice per turn by prebuffing it.
Definitely agree that these ranger abilities are great candidates to get the “Divine Smite” treatment now that Larian have updated their engine to better cope with reactions and reaction-like conditional actions. Good point!